Trussed girder.



PATENTE AUG. 13, 19u?. LKAHN.

TRUssED GAIRDER. VAPPLXOATIH FILED APB.. l5, 1907. y

2 SHEETS-*SHEET 1.

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' witnesses Inven'o,

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Attorneys PATENTED AUG; 13, 1907.

J.KAHN. TRUSSBD GIRDBR. APPLIOATION FIIBD APB. 15, 1907.

2 SHEETS-SHEET 2.

UNrTnn ysTiiTns .llfllIUS KIlN, OIF DETROIT, MICHIGAN.

TRUssED GIRDER.

Specification of Letters Patent.

Patented Aug'. 13, 1907.

Application filed April l5, 1907. Serial No- 368,413.

To all whom. it may roncr'rn.:

ly my present invention I provide a. beam embodylle it known that I, .TULiUs HAHN, a citizen of thev inglhe principles oia truss with itsadvantages ofligluf- United States, and a resident of Detroit, in the county a of Wayne and State of Michigan, have invented a new and Improved Trusscd Girder, of which the following is a specification. l

The strength of nfetal beams and girders depends generally on the upper and lower flanges, and on the distance between them. With few exceptions, the

u'sual I beams are not of the most economical design so far as material is concerned, their dimensionsbeing determined moreby the problems o manufacturing that must be overcomethan the necessary strength of the parts. Inhvthe larger percentage of beamsfand girders much metal could be safely cut out of tlie Webs without weakening the structure, but the value of the metal thus cut out would be much less than the c ost oi the labor required to remove it.

My invention consists in t trussed girder in which;-

the greatest possible strength is' obtained for the amountoi material employed; or in other words, it consists in a. girder or beamwhich offers the most economic structure possible for the desired strength, cost of material and cost of labor both being considered.

.My invention consists in atru'ssed structureformed from properly rolled bars or beams, the middleportion of each of which is slotted or sheared,- and the outer perf tions expanded to form a portion of a-truss.

1t consists further in combininga plurality f these part trusses to form a complete truss.

It consists further in so forming the contiguous faces l.

of the part trussesthat they will properly interlock to insure perfect union. l I

A1 attain my invention inthe constructions-illu'strated in the accompanying drawings, lin which Figure 1 is a side view of my complete trussed girder."

Fig. 2 is a view of a'beam properly rolled, machined and ready to'be expanded to form one member of my' improved girder. Fig. 3 is a cross section on the line 3 3 of Fig. l. Fig. 4 is a cross section on the line of Fig. 2. Fig. 5 is across section oa box girder-formed with two of improved trussed girders. Fig. 6 is a view of a modified form of my improved girder.. Fig.

' is a view of a beam properly machined ready for ein.`

panding. Fig. 6.

Similar reference lcharacters refer to like parte throughout the several views.

As the factors which det'ermine the strength of a beam or girder in bending arethe cross-sectional area of the upper and lower flanges and thedistance between these flanges and the neutral-axis, it follows that for equal weights of beams, particularly for long spans, the depth of the beam will generally determine its value. The web o the beam need be of but little greater strength- Fig. 8 is a -cross section on the line 8`S of than sufficient. to withstand the crushing of the load.

ness and correct proportion, vin contra-distinction to the usual plate girder .which is formed with a web plate of oven thickness, and unnecessary weight.

ln forming my improved girder, ,a channel beam rolled with flanges 1 and 2j. (see Fig. A) and with flut portions 3 and 1, grooves 5, (i and '7,A and ridges S and 9.

The beam then shea-red 'or punched as shown 'n1 Fig. V65

2, the web being now composed ol' the members?? und 9 connected 'together at their right onds by -tle plale`1l0. and having their opposite ends secured to the angles l-3 and 2-4 by thc connections 11. The partsl are formed with-a bead or ridgev l.Z adapted to fit a groove 13 in an adjacent member, as shown in Fig. S forming the'wellknown. tongue-and-grolvo joint. Holes H are punched where desired and the 'beam is expanded by 1noving the angles away from each other.

When the anglesare scpam1cd, 'tl1e parts S will bend at the connections l1. and at the plates 10, as shown in Fig. 1. been prepa-red' (with its bcad'or ridg(` 12 at the bottom insinad oi at thelopl'it is secured to the first portion of the truss.l Plates 15 are secured between the ends ofl S0' Athe part trusscsas shown in Fig. l, to properlyt-.rlre

the .thrust of the supports. Y' l The'angles and plates 10 of they two part trusses are connected by -rivets and the trussed girder is complete. T he upper, lower andv diagonal members of 35v these girders will act as truss members inuthc usual 1m1.nn\r .y When greater stilfnessis .desir-echa pair oiftlieselrusses may be' -connected.by upper and lowcr plates 17 to form a .b ox girder as shown. in Fig. 5: W'lwu astiffer stronger web is .de'sirod,4 the conslructimi 90 shownnFigs. 6, 7 and-8 may hecm'ploycd. lThe up;

l, per and lower. angles are fornud'by the parts '.l-ll und 2--4,'and` these 'portions of the two part-trusses 'are connccted bythe longues 12 fitting into grooves in -thc' other member as before described.' .instead .of one 95 l'diagonal member connecting to the lower longitudimil member, the two diagonal `men1bers joining at the neutral axis, the construction i's modified as follows. Referring to Fig. 7, thebemu is machined to vform transverse slots 250 and lateral slots 21 extending lherc- 10() .from. This leavesfrcctang'ular portions 'connected lo vthenpper and lowermembers by theparls 22. These .rectangular members are then shear-ed forming rods 23 and 24, connectcdin pairs at their ends.'v The web oi the original beam may 'be so rolled that these rods 23 .1.05

-and 24 have considerable depth. Theupperandlower l members are then separated, and two part trusses are secured together as shown i'n Fig. li, byrivcts through the webs il and 'iQ- and througli the joined pi irl ions of tln` rods 23 and. 24. The lattice illus formed will be ver \r' l10 stiff, because of the many points of unioifbotweeu the diagonal members of the truss. .The ends may be and 9 75 A companion part truss having stiffened byadding theplate 26. By these construe# tions, a girderis provided in which the upper and lower'.

members may have any desired weight, While atthe same time the web has no unnecessary metal.

In many cases, the ordinary I beams cannot be emv ployed to c arry even light loads on 4extreme spans, as

, and an-open-work intermediate portion integral therewith formed of connected oppositely inclined parts.`

2; trussed girder built up from a plurality of parttrusses, each part-truss comprising a longitudinal upper member, a longitudinal lower member, and diagonal members extending-inwardly from the longitudinal members' and joined at their ends `to the diagonal members of the other part-truss.

3. A trussed girder comprising a plurality of similar part-trusses secured together, the longitudinal portions of the parttrusses being held in alinement by interlocking projections.

4. A trussedgirder formed by securing together two similar part-trusses.' each part-'truss comprising longitudinal,upper and lower members and diagonal members extending inwardly from the longitudinal members a portion of the distance between them,fthe diagonal members of one partltruss 'being secured a't their ends to the ends of similar members of the'otherA part-truss.

5. A trussedl girder `formed by securingv together two similar part-trussesfeach comprisinglongitudinal up er and lower members and diagonal members integral there-i 35 with, eacli'of the diagonals ofthe irussed girderbeing com. posed oi. diagonal members of both part-trusses secured togetherat their ends., Y j'v 6. A -trnssd girderi'ormed by securingv together two similar part trusses,vvea ch comprising longitudinal upper und lower sections and an openwork section between them, the open work section being formed from short oppositely inclined diagonal bars integral' with the longitudinal members, andhaving adjacentends vjoined, the joined ends of the diagonal bars: forming, tiie'open vwork section `of 'the two part trussesjbeing connected.

7. A trussed girlier .comprising 'piuralit-y of similar part-trusses, and means .to hold the longitudinal portions of the part-trusses in alinement.

8: A structural member. formed by securing together a pluralityv of parts, e'ch comprising longitudinal members, and connecting members integral therewith, extending in- -ward1y from said longitudinal members and connectedat their ends to the connecting members of another part.

In testimony whereof Ihave signed this application in the presence of two subscribing witnesses.

JULIUs KAHN.

Witnesses:

' W. N. SALTER,

E. N. PAGnLsnN. 

